linux/arch/cris/arch-v32/kernel/head.S
Jesper Nilsson c5ec6fb08d [CRIS] Remove links from CRIS build
Remove the links to architecture and machine dependent directories
(boot, lib, drivers, arch, mach)

The links were created and used mostly from the arch/cris/Makefile,
so why not dispense with them altogether?
Changed $(ARCH) to "cris" in Makefile, it is easier to read this way.

The CRISv32 head.S common files for the kernel and compressed images
needed to be modified to use ifdefs instead of using the now removed
mach link. Since there are only two versions, this is not a huge loss
in readability.

The link to vmlinux.lds.S is also replaced with a merged version
which uses ifdefs to select the correct layout.
System.map before and after are identical.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
2008-10-31 23:37:57 +01:00

489 lines
13 KiB
ArmAsm

/*
* CRISv32 kernel startup code.
*
* Copyright (C) 2003, Axis Communications AB
*/
#define ASSEMBLER_MACROS_ONLY
/*
* The macros found in mmu_defs_asm.h uses the ## concatenation operator, so
* -traditional must not be used when assembling this file.
*/
#include <linux/autoconf.h>
#include <arch/memmap.h>
#include <hwregs/reg_rdwr.h>
#include <hwregs/intr_vect.h>
#include <hwregs/asm/mmu_defs_asm.h>
#include <hwregs/asm/reg_map_asm.h>
#include <mach/startup.inc>
#define CRAMFS_MAGIC 0x28cd3d45
#define JHEAD_MAGIC 0x1FF528A6
#define JHEAD_SIZE 8
#define RAM_INIT_MAGIC 0x56902387
#define COMMAND_LINE_MAGIC 0x87109563
#define NAND_BOOT_MAGIC 0x9a9db001
;; NOTE: R8 and R9 carry information from the decompressor (if the
;; kernel was compressed). They must not be used in the code below
;; until they are read!
;; Exported symbols.
.global etrax_irv
.global romfs_start
.global romfs_length
.global romfs_in_flash
.global nand_boot
.global swapper_pg_dir
;; Dummy section to make it bootable with current VCS simulator
#ifdef CONFIG_ETRAX_VCS_SIM
.section ".boot", "ax"
ba tstart
nop
#endif
.text
tstart:
;; This is the entry point of the kernel. The CPU is currently in
;; supervisor mode.
;;
;; 0x00000000 if flash.
;; 0x40004000 if DRAM.
;;
di
START_CLOCKS
SETUP_WAIT_STATES
GIO_INIT
#ifdef CONFIG_SMP
secondary_cpu_entry: /* Entry point for secondary CPUs */
di
#endif
;; Setup and enable the MMU. Use same configuration for both the data
;; and the instruction MMU.
;;
;; Note; 3 cycles is needed for a bank-select to take effect. Further;
;; bank 1 is the instruction MMU, bank 2 is the data MMU.
#ifndef CONFIG_ETRAX_VCS_SIM
move.d REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 8) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 4) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb), $r0
#else
;; Map the virtual DRAM to the RW eprom area at address 0.
;; Also map 0xa for the hook calls,
move.d REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 8) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 4) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0xa), $r0
#endif
;; Temporary map of 0x40 -> 0x40 and 0x00 -> 0x00.
move.d REG_FIELD(mmu, rw_mm_kbase_lo, base_4, 4) \
| REG_FIELD(mmu, rw_mm_kbase_lo, base_0, 0), $r1
;; Enable certain page protections and setup linear mapping
;; for f,e,c,b,4,0.
#ifndef CONFIG_ETRAX_VCS_SIM
move.d REG_STATE(mmu, rw_mm_cfg, we, on) \
| REG_STATE(mmu, rw_mm_cfg, acc, on) \
| REG_STATE(mmu, rw_mm_cfg, ex, on) \
| REG_STATE(mmu, rw_mm_cfg, inv, on) \
| REG_STATE(mmu, rw_mm_cfg, seg_f, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_e, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_d, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_c, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_b, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_a, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_9, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_8, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_7, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_6, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_5, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_4, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_3, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_2, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_1, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_0, linear), $r2
#else
move.d REG_STATE(mmu, rw_mm_cfg, we, on) \
| REG_STATE(mmu, rw_mm_cfg, acc, on) \
| REG_STATE(mmu, rw_mm_cfg, ex, on) \
| REG_STATE(mmu, rw_mm_cfg, inv, on) \
| REG_STATE(mmu, rw_mm_cfg, seg_f, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_e, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_d, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_c, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_b, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_a, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_9, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_8, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_7, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_6, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_5, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_4, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_3, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_2, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_1, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_0, linear), $r2
#endif
;; Update instruction MMU.
move 1, $srs
nop
nop
nop
move $r0, $s2 ; kbase_hi.
move $r1, $s1 ; kbase_lo.
move $r2, $s0 ; mm_cfg, virtual memory configuration.
;; Update data MMU.
move 2, $srs
nop
nop
nop
move $r0, $s2 ; kbase_hi.
move $r1, $s1 ; kbase_lo
move $r2, $s0 ; mm_cfg, virtual memory configuration.
;; Enable data and instruction MMU.
move 0, $srs
moveq 0xf, $r0 ; IMMU, DMMU, DCache, Icache on
nop
nop
nop
move $r0, $s0
nop
nop
nop
#ifdef CONFIG_SMP
;; Read CPU ID
move 0, $srs
nop
nop
nop
move $s12, $r0
cmpq 0, $r0
beq master_cpu
nop
slave_cpu:
; Time to boot-up. Get stack location provided by master CPU.
move.d smp_init_current_idle_thread, $r1
move.d [$r1], $sp
add.d 8192, $sp
move.d ebp_start, $r0 ; Defined in linker-script.
move $r0, $ebp
jsr smp_callin
nop
master_cpu:
/* Set up entry point for secondary CPUs. The boot ROM has set up
* EBP at start of internal memory. The CPU will get there
* later when we issue an IPI to them... */
move.d MEM_INTMEM_START + IPI_INTR_VECT * 4, $r0
move.d secondary_cpu_entry, $r1
move.d $r1, [$r0]
#endif
#ifndef CONFIG_ETRAX_VCS_SIM
; Check if starting from DRAM (network->RAM boot or unpacked
; compressed kernel), or directly from flash.
lapcq ., $r0
and.d 0x7fffffff, $r0 ; Mask off the non-cache bit.
cmp.d 0x10000, $r0 ; Arbitrary, something above this code.
blo _inflash0
nop
#endif
jump _inram ; Jump to cached RAM.
nop
;; Jumpgate.
_inflash0:
jump _inflash
nop
;; Put the following in a section so that storage for it can be
;; reclaimed after init is finished.
.section ".init.text", "ax"
_inflash:
;; Initialize DRAM.
cmp.d RAM_INIT_MAGIC, $r8 ; Already initialized?
beq _dram_initialized
nop
#if defined CONFIG_ETRAXFS
#include "../mach-fs/dram_init.S"
#elif defined CONFIG_CRIS_MACH_ARTPEC3
#include "../mach-a3/dram_init.S"
#else
#error Only ETRAXFS and ARTPEC-3 supported!
#endif
_dram_initialized:
;; Copy the text and data section to DRAM. This depends on that the
;; variables used below are correctly set up by the linker script.
;; The calculated value stored in R4 is used below.
;; Leave the cramfs file system (piggybacked after the kernel) in flash.
moveq 0, $r0 ; Source.
move.d text_start, $r1 ; Destination.
move.d __vmlinux_end, $r2
move.d $r2, $r4
sub.d $r1, $r4
1: move.w [$r0+], $r3
move.w $r3, [$r1+]
cmp.d $r2, $r1
blo 1b
nop
;; Check for cramfs.
moveq 0, $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
move.d [$r4], $r0 ; cramfs_super.magic
cmp.d CRAMFS_MAGIC, $r0
bne 1f
nop
;; Set length and start of cramfs, set romfs_in_flash flag
addoq +4, $r4, $acr
move.d [$acr], $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
add.d 0xf0000000, $r4 ; Add cached flash start in virtual memory.
move.d romfs_start, $r1
move.d $r4, [$r1]
1: moveq 1, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
jump _start_it ; Jump to cached code.
nop
_inram:
;; Check if booting from NAND flash; if so, set appropriate flags
;; and move on.
cmp.d NAND_BOOT_MAGIC, $r12
bne move_cramfs ; not nand, jump
moveq 1, $r0
move.d nand_boot, $r1 ; tell axisflashmap we're booting from NAND
move.d $r0, [$r1]
moveq 0, $r0 ; tell axisflashmap romfs is not in
move.d romfs_in_flash, $r1 ; (directly accessed) flash
move.d $r0, [$r1]
jump _start_it ; continue with boot
nop
move_cramfs:
;; kernel is in DRAM.
;; Must figure out if there is a piggybacked rootfs image or not.
;; Set romfs_length to 0 => no rootfs image available by default.
moveq 0, $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
#ifndef CONFIG_ETRAX_VCS_SIM
;; The kernel could have been unpacked to DRAM by the loader, but
;; the cramfs image could still be in the flash immediately
;; following the compressed kernel image. The loader passes the address
;; of the byte succeeding the last compressed byte in the flash in
;; register R9 when starting the kernel.
cmp.d 0x0ffffff8, $r9
bhs _no_romfs_in_flash ; R9 points outside the flash area.
nop
#else
ba _no_romfs_in_flash
nop
#endif
;; cramfs rootfs might to be in flash. Check for it.
move.d [$r9], $r0 ; cramfs_super.magic
cmp.d CRAMFS_MAGIC, $r0
bne _no_romfs_in_flash
nop
;; found cramfs in flash. set address and size, and romfs_in_flash flag.
addoq +4, $r9, $acr
move.d [$acr], $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
add.d 0xf0000000, $r9 ; Add cached flash start in virtual memory.
move.d romfs_start, $r1
move.d $r9, [$r1]
moveq 1, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
jump _start_it ; Jump to cached code.
nop
_no_romfs_in_flash:
;; No romfs in flash, so look for cramfs, or jffs2 with jhead,
;; after kernel in RAM, as is the case with network->RAM boot.
;; For cramfs, partition starts with magic and length.
;; For jffs2, a jhead is prepended which contains with magic and length.
;; The jhead is not part of the jffs2 partition however.
#ifndef CONFIG_ETRAXFS_SIM
move.d __vmlinux_end, $r0
#else
move.d __end, $r0
#endif
move.d [$r0], $r1
cmp.d CRAMFS_MAGIC, $r1 ; cramfs magic?
beq 2f ; yes, jump
nop
cmp.d JHEAD_MAGIC, $r1 ; jffs2 (jhead) magic?
bne 4f ; no, skip copy
nop
addq 4, $r0 ; location of jffs2 size
move.d [$r0+], $r2 ; fetch jffs2 size -> r2
; r0 now points to start of jffs2
ba 3f
nop
2:
addoq +4, $r0, $acr ; location of cramfs size
move.d [$acr], $r2 ; fetch cramfs size -> r2
; r0 still points to start of cramfs
3:
;; Now, move the root fs to after kernel's BSS
move.d _end, $r1 ; start of cramfs -> r1
move.d romfs_start, $r3
move.d $r1, [$r3] ; store at romfs_start (for axisflashmap)
move.d romfs_length, $r3
move.d $r2, [$r3] ; store size at romfs_length
#ifndef CONFIG_ETRAX_VCS_SIM
add.d $r2, $r0 ; copy from end and downwards
add.d $r2, $r1
lsrq 1, $r2 ; Size is in bytes, we copy words.
addq 1, $r2
1:
move.w [$r0], $r3
move.w $r3, [$r1]
subq 2, $r0
subq 2, $r1
subq 1, $r2
bne 1b
nop
#endif
4:
;; BSS move done.
;; Clear romfs_in_flash flag, as we now know romfs is in DRAM
;; Also clear nand_boot flag; if we got here, we know we've not
;; booted from NAND flash.
moveq 0, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
moveq 0, $r0
move.d nand_boot, $r1
move.d $r0, [$r1]
jump _start_it ; Jump to cached code.
nop
_start_it:
;; Check if kernel command line is supplied
cmp.d COMMAND_LINE_MAGIC, $r10
bne no_command_line
nop
move.d 256, $r13
move.d cris_command_line, $r10
or.d 0x80000000, $r11 ; Make it virtual
1:
move.b [$r11+], $r1
move.b $r1, [$r10+]
subq 1, $r13
bne 1b
nop
no_command_line:
;; The kernel stack contains a task structure for each task. This
;; the initial kernel stack is in the same page as the init_task,
;; but starts at the top of the page, i.e. + 8192 bytes.
move.d init_thread_union + 8192, $sp
move.d ebp_start, $r0 ; Defined in linker-script.
move $r0, $ebp
move.d etrax_irv, $r1 ; Set the exception base register and pointer.
move.d $r0, [$r1]
#ifndef CONFIG_ETRAX_VCS_SIM
;; Clear the BSS region from _bss_start to _end.
move.d __bss_start, $r0
move.d _end, $r1
1: clear.d [$r0+]
cmp.d $r1, $r0
blo 1b
nop
#endif
#ifdef CONFIG_ETRAX_VCS_SIM
/* Set the watchdog timeout to something big. Will be removed when */
/* watchdog can be disabled with command line option */
move.d 0x7fffffff, $r10
jsr CPU_WATCHDOG_TIMEOUT
nop
#endif
; Initialize registers to increase determinism
move.d __bss_start, $r0
movem [$r0], $r13
#ifdef CONFIG_ETRAX_L2CACHE
jsr l2cache_init
nop
#endif
jump start_kernel ; Jump to start_kernel() in init/main.c.
nop
.data
etrax_irv:
.dword 0
; Variables for communication with the Axis flash map driver (axisflashmap),
; and for setting up memory in arch/cris/kernel/setup.c .
; romfs_start is set to the start of the root file system, if it exists
; in directly accessible memory (i.e. NOR Flash when booting from Flash,
; or RAM when booting directly from a network-downloaded RAM image)
romfs_start:
.dword 0
; romfs_length is set to the size of the root file system image, if it exists
; in directly accessible memory (see romfs_start). Otherwise it is set to 0.
romfs_length:
.dword 0
; romfs_in_flash is set to 1 if the root file system resides in directly
; accessible flash memory (i.e. NOR flash). It is set to 0 for RAM boot
; or NAND flash boot.
romfs_in_flash:
.dword 0
; nand_boot is set to 1 when the kernel has been booted from NAND flash
nand_boot:
.dword 0
swapper_pg_dir = 0xc0002000
.section ".init.data", "aw"
#if defined CONFIG_ETRAXFS
#include "../mach-fs/hw_settings.S"
#elif defined CONFIG_CRIS_MACH_ARTPEC3
#include "../mach-a3/hw_settings.S"
#else
#error Only ETRAXFS and ARTPEC-3 supported!
#endif